German patent document DE 10 2009 001 401 A1 discusses a brake system, a method for operating a brake system, and a production method for a brake system. The brake system has a first brake circuit that is connected to a main brake cylinder via an isolation valve. By closing the isolation valve, the wheel brake cylinder of the first brake circuit can be decoupled from the main brake cylinder. Thus, using a pump and/or using a continuously adjustable valve of the first brake circuit, a brake pressure present therein can be varied independently from an internal pressure in the main brake cylinder.